The prior art related to water purification systems includes systems in which wastewater is introduced into a contact chamber in which an ultraviolet lamp has been placed. In the past, the path length along which the wastewater can flow was limited to the length of the ultraviolet lamp. For example, if the ultraviolet lamp was 30 inches long, then the length of the contact chamber was approximately 30 inches long. In an effort to overcome this size limitation which limits the amount of ultraviolet energy which is available for water purification purposes, attempts have been made to design contact chambers in which the water flow is perpendicular to a plurality of ultraviolet lamps. These designs have not been successful because water flow at high linear velocities, due to high flow rates, impinging perpendicu1arly on the quartz jackets, which surround and protect the ultraviolet lamps, results in a severe strain on these quartz jackets. This limits the maximum flow attainable through the contact chamber and limits the water purification capability of the apparatus.
The maximum length of a conventional ultraviolet lamp is a function of a series of complex design factors which limit the maximum length. These factors include: the design of the electrodes, the electrical energy available and the mechanical strength of the cylinder which supports the electrodes. These and other design factors limit the maximum length of a conventional ultraviolet lamp.
It is an object of the present invention to provide an ultraviolet light source having an extended length which is substantially longer than the length of an individual ultraviolet lamp.
Another object of the present invention is to provide an ultraviolet lamp which requires electrical connection only at one end.
Another object of the present invention is to provide an ultraviolet lamp which can be inserted into a quartz tube which is sealed at one end.
Another object of the present invention is to provide an ultraviolet light source, the length of which is not limited by the length of an individual ultraviolet lamp.
Another object of the present invention is to provide an ultraviolet lamp which can be used effectively in a water treatment contact chamber in which the flow of water is parallel to the lamp.
Another object of the present invention is to provide an ultraviolet light source which is extremely rugged and reliable permitting its uses in applications which require high wastewater flow rates.
Still another object of the invention is to provide an ultraviolet lamp which is capable of being used in a parallel flow contact chamber having a high ratio of length to width.
A further object of the invention is the provision of a lamp structure which requires electrical connection at only one end and which may be incorporated in various types of tubular gaseous discharge lamps, such as fluorescent lamps, where electrical connection at one end and/or arrangement of the lamps in a linear series is desired.